One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to estimate when it's possible to plant helianthemum by using the USDA zone info for Defiance.

Planting Calendar for Helianthemum

Frost tolerance for helianthemum:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant helianthemum a bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant helianthemum in Defiance is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant helianthemum and expect a good harvest is probably September. If you wait any later than that and your helianthemum may not have a chance to fully mature. You can get started a few weeks earlier by starting your helianthemum indoors.

Last Frost Date

The average date of last frost is April 15 in Defiance. You can expect an average low temperature of -10°F in the coldest months of winter.

It's important to remember that USDA zone info for Defiance may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Since half of the time in Defiance it frosts late in the year after April 15 be ready to cover your helianthemum if you have one of those late frosts.

USDA Zone Info for Defiance

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Defiance

You may be interested in your other planting guides for Defiance.